1. Field of the Invention
This invention relates to a device for tying down cargo loads on a vehicle such as an aircraft and more particularly to such a device which is capable of handling heavy loads supported on pallets.
2. Description of the Related Art
Prior art devices for tying down Cargo on a vehicle such as an aircraft are described in U.S. Pat. No. 4,540,080 issued to Nordstrom on Sep. 10, 1985 and U.S. Pat. No. 3,377,040 issued Apr. 9, 1968 to Hansen. These prior art devices are directed to restraining the movement of a cargo bearing pallet by means of a restraining arm which is positioned over the edge of a pallet to hold it in place. This device has the disadvantage of being inadequate for handling heavy loads which require greater restraint and support. Further, many of such devices are overly complicated in their construction and utilization and do not provide low friction support of the pallet which is necessary in positioning heavy loads in their final resting position.
The device of the invention overcomes the shortcomings of the prior art in providing adequate restraint for heavy cargo loads mounted on pallets in a vehicle such as an aircraft. The present invention enables rapid installation and removal of the restraints, permitting the pallets to be slid in on rollers to the restraint position where they are secured in place with latches. The device employs a plurality of rail assemblies which have two main portions which are connected together. These two portions comprise a cross track and a compression bar which provides a compression force on the cross tracks. One end of the cross tracks has shear lugs attached thereto which are fitted into a track having cutout portions separated from each other by lip portions. The track is mounted on the floor of the vehicle and provides support for the cross tracks on this end. Each cross track and compression bar are connected together and to a cross rail.
The end of each compression bar opposite to that attached to the associated cross bar abuts against a bar in a tensioned condition, this bar being attached to the vehicle floor. Each compression bar is attached to a second cross rail spaced from the rail to which it is attached, along with the cross track. Mounted on the inner end of each rail assembly is a latch device which has a tongue which fits into a cavity in the bottom of the pallet. These latch devices can be manually actuated to either latch the rail support assemblies to the pallet or release them therefrom to permit removal of the pallet. Rollers are installed on the rail support assemblies to facilitate loading and unloading of the pallet. The device of the invention thus provides a high strength pallet support which is capable of handling heavy loads and yet is of relatively simple and economical construction.